I assume its just a lack of writer interest. It would be a relatively simple matter to handwave Hope downloading one of Tyler's back-ups into a teen husk of him and cutting it off before it got to the point where he was kidnapped & brainwashed by Stryfe. Pretty sure just outside of the Steves aka the Deep Cut Kings, nobody else even really remembers he existed, and Cable & Hope have been largely handled by writers others than those two.